MySQL SystemQA: Testing MEB impact over MySQL Server features:

     MySQL SysQA team is responsible to test the MySQL Enterprise backup at a system level. Along with the System testing , SysQA team worked on MEB impact over MySQL Server features to ensure the new version of MySQl server is compatible with latest release of MEB.

What we do.

- Analyse each Server feature and findout if that impacts MEB.

- Run an Automated test that integrates the server functionalities along with MEB. The test is done in parallel with running server feature.

- Run the feature at each level of MEB run and verify if it works fine.

- Run the feature at different boundary conditions and verify the backup.

How we Did.

- Created a MultiThreaded program to run the MEB and Server feature in parallel.

- Run different transactions …

I recently had to do a backup of a 30 very large databases within a MySQL instance that had a total of 60+ databases.  I did NOT want to back up the other databases. In fact, the other databases had very large tables in them and I had very little disk space, so I could not afford to back them up. In this post I will share what I learned.

I’ve simplified the problem to illustrate the idea.  My goal in this post is to backup one database when an instance has many, with mixed InnoDB and MyIsam tables.

• I have 3 databases called dbtest1, dbtest2, and dbtest3, in one instance of MySQL .  I only want to back up  the tables in database dbtest2

• Each database has one InnoDB and one MyISAM table
• The InnoDB tables are quite large, and I have limited disk space …

MySQL 5th Edition by Paul Dubois

MySQL by Paul Dubois recently was reissued in a fifth edition. I purchased my first edition of this book more than a dozen years ago and it has become heavily dog-eared, festooned with Post-Its, and hand annotated over the years. It has proven to be the ‘go-to’ book when other books or the manuals did not explain to my satisfaction any questions that have popped up.

The author is part of the amazing MySQL Documentation Team for Oracle and certainly knows the subject. At 1,154 pages it is not light in weight nor light in detail. The chapters include ‘Data Types’, ‘Writing MySQL Programs using C’, ‘Security and Access Control’, ‘System, Status and User Variable …

You’ve just completed an upgrade from MySQL 5.5 to 5.6.  You followed the upgrade instructions in the manual, and ran mysql_upgrade.  But when you start MySQL 5.6, you still see the following error messages like the following in the server error log:

2013-03-26 16:45:51 5040 [ERROR] Column count of mysql.events_waits_current is w
rong. Expected 19, found 16. Created with MySQL 50520, now running 50610. Please
use mysql_upgrade to fix this error.
2013-03-26 16:45:51 5040 [ERROR] Column count of mysql.events_waits_history is w
rong. Expected 19, found 16. Created with MySQL 50520, now running 50610. Please
use mysql_upgrade to fix this error.

What went wrong?

Well, because mysql_upgrade is a client that’s built for a specific server version, it’s possible you have two …

Percona Server for MySQL version 5.6.11-60.3

Percona is glad to announce the first Release Candidate release of Percona Server 5.6.11-60.3 on June 3rd, 2013 (Downloads are available here and from the Percona Software Repositories).

Based on MySQL 5.6.11, including all the bug fixes in it, Percona Server 5.6.11-60.3 is the first RC release in the Percona Server 5.6 series. All of …

Many MySQL users are familiar with using slow query logs and tools such as mysqldumpslow to identify poor-performing SQL commands, and MySQL 5.6 introduces new powerful tools in PERFORMANCE_SCHEMA.  Both allow you to identify the date/time and the user account from which the command was issued, which is helpful – but if you’re using MySQL Enterprise Monitor (MEM), you can immediately identify the actual line of code responsible for the SQL command in question.  This happens to be one of my favorite and powerful features of MEM, but it’s frequently overlooked by new and experienced MEM users alike, so I’m writing the post to highlight it.

MySQL Enterprise Monitor, of course, is a commercial product that’s part of the MySQL Enterprise subscription.  But it’s freely-available under 30-day trial terms for evaluation from Oracle Software Delivery Cloud – if …

This is what I’m talking about, this is fantastic news! Anxiously looking forward to the WB 6.0 public Beta test phase for Mac / OS X…hopefully soon?

Over several blog posts, Tim has presented performance results on large data sets of TokuMX, our MongoDB product with fractal tree indexes integrated, side by side with MongoDB. Results look good. We’ve shown improved throughput numbers on a sysbench benchmark, faster load times, and high compression.

So what is TokuMX, and how does it achieve this performance?

TokuMX has replaced ALL of the storage code in MongoDB with fractal trees. Every collection, every secondary index, every metadata collection is stored with fractal trees, the same technology that implements the TokuDB storage engine for MySQL. That is, all data is stored and managed with our transactional, ACID and MVCC-compliant, write-optimized storage library.

TokuMX achieves …

On Friday I gave a presentation on “MySQL Query Patterns, Optimized” for Percona MySQL Webinars.  If you missed it, you can still register to view the recording and my slides.

Thanks to everyone who attended, and especially to folks who asked the great questions.  I answered as many as we had time for  during the session, but here are all the questions with my complete answers:

Q: Can you compare the use of subqueries/multiple joins vs. multiple queries (e.g. temp tables)?

For performance, it’s hard to make …

Back in November, I filed MySQL bug 67448, talking about a different type of max_allowed_packet problem.

See, an application had put data into the database, but could not retrieve it without getting max_allowed_packet. With the help of some really smart community folks (named Jesper Hansen, Brandon Johnson and Shane Bester), we determined that MySQL actually has 2 different max_allowed_packet settings: client and server.

When you change the max_allowed_packet variable, you are changing the server variable if it is in [mysqld] and the client variable if it is in [client] or [mysql] or whatever client you have. As far as we can tell, there’s no way to actually view what the client variable is, as looking at both the session and global max_allowed_packet variable shows you the server variable.

If max_allowed_packet is not set by the client, it defaults to …